def test_as_filelike():
buf = BytesIO(b'hello world')
f = as_filelike(buf)
if PYX:
assert isinstance(f, FileLike)
else:
assert f is buf
assert f.read(5) == b'hello'
assert f.read() == b' world'
def test_segments():
header = b('\x03\x00\x00\x00' # 3+1 segments
'\x10\x00\x00\x00' # size0: 16
'\x20\x00\x00\x00' # size1: 32
'\x40\x00\x00\x00' # size2: 64
'\x10\x00\x00\x00' # size3: 16
'\x00\x00\x00\x00') # padding
payload = b'\x00'*16*8 + b'\x00'*32*8 + b'\x00'*64*8 + b'\x00'*16*8
buf = header + payload
f = BytesIO(buf)
msg = _load_message(as_filelike(f))
assert f.tell() == len(buf)
assert msg._data_offset == 0
assert msg._seg.segment_offsets == (0, 16*8, (16+32)*8, (16+32+64)*8)
assert msg._seg.buf == payload
def load(f, payload_type):
"""
Load a message of type ``payload_type`` from f.
The message is encoded using the recommended capnp format for serializing
messages over a stream:
- (4 bytes) The number of segments, minus one (since there is always at
least one segment)
- (N * 4 bytes) The size of each segment, in words.
- (0 or 4 bytes) Padding up to the next word boundary.
- The content of each segment, in order.
"""
f2 = as_filelike(f)
msg = _load_message(f2)
return msg._read_struct(0, payload_type)
